French physiologist. Born July 12, 1813 ({sys: (year (now) -1813) in Villefranche, France, died February 10, 1878 in Paris. In 1834, he went to the Faculty of Medicine of the French Academy in Paris to study medicine. In 1839, he worked as an intern in the laboratory of F. Magendi, professor of physiology. Graduated from medical school in 1843. At the end of 1847, he became Magendi's official assistant. After Magendi retired in 1852, he succeeded Magendi as professor of physiology and director of the physiology laboratory of the French Academy. In March 1853, he received a doctorate in zoology from the University of Paris. In 1854, he was elected to the French Academy of Sciences. From 1854 to 1868, he served as professor of physiology at the Faculty of Sciences of the University of Paris, and in 1868 he was transferred to professor of physiology at the Museum of Natural History. In 1869, he was appointed president of the French Academy of Sciences.

In his long-term cooperation with Magendi, he used vivisection as the main means of physiological research. He surpassed his teachers in the creation of experimental techniques, the discovery of scientific facts, and the establishment of new concepts. He became one of the founders of modern physiology. He discovered that the liver has the function of generating glycogen, the vasomotor is controlled by nerves, the pancreatic juice can digest fat, the nature and function of curare in America, and the toxicity of carbon monoxide. He rejected the widely accepted understanding that sugar in animal blood comes directly from food and that animals cannot synthesize polysaccharides, and used a large number of experimental facts to show that sugar in blood does not come directly from food but from the liver. The liver can store glucose into glycogen, and liver glycogen can be broken down into glucose and sent back to the blood for the body's needs. He made an important addition to A.L. Lavoisier's view that "respiration is slow combustion (i.e. oxidation) ", arguing that the oxidation process in an organism is not the direct combustion of oxygen and carbon, but the indirect oxidation that occurs through the action of enzymes. The site of oxidation is not only the lungs, but also the entire tissue of the body. He disagreed with the "vitality theory" that was popular at the time, and firmly believed that the vitality was chemical force. Bernard began to explore from 1851 and formally proposed the important concept of biological "internal environment" in 1857. It is believed that an organism lives in the external environment to which it is accustomed, while various tissues in an organism live in the "internal environment" of the organism. The stability of the internal environment is the prerequisite for the existence of life; the internal environment must always be in balance with the external environment, otherwise the phenomenon of life will be disturbed. His ideas in this area still have an important influence today. His book Introduction to Experimental Medicine, published in 1865, is considered a milestone in the history of physiology. When he died, France held a state funeral.